Red Line Components Posted October 25, 2016 Share Posted October 25, 2016 The Car: 1968 S2, 1500 pre crossflow, single weber, mechanical fuel pump.The engine stopped out of the blue, symptoms similar to running out of fuel. Bonnet off and glass inline fuel filter located between the tank and the pump was empty.Added some fuel (but actually the tank was found to be almost full) and the car started and ran for a mile or 2 before the same thing happened.I suspected dirt in the tank/fuel line preventing the fuel from reaching the filter and pump.Back in the garage, after cleaning the fuel lines and replacing the filter I try again, fuel is pumping OK (with the fuel line into carb disconnected) but no hint of firing up once connected to the carb.Lots of cranking, plugs sparking but dry.I now suspect a failing weak fuel pump or some sort of block in the carb. But this wouldn't have caused the empty filter.I think i will replace the pump next (as this is a simple swap and I can rob the project car of a good pump)....Thoughts? Link to comment Share on other sites More sharing options...
paul_w Posted October 25, 2016 Share Posted October 25, 2016 I've had similar where there was crud in the tank - as the fuel is drawn through the pick up it gradually attracts the crud and blocks the end of the pickup. the car sits and all the crud falls to the bottom of the tank again, so it starts up again fine and runs for a while. An old Spitfire I had drove me mad with this, and when I pulled the tank and drained it I found a pile of leaves in it (I can only assume put in there as a 'hilarious' prank...) Link to comment Share on other sites More sharing options...
Englishmaninwales Posted October 25, 2016 Share Posted October 25, 2016 The pump may have failed. Possibly the one way valves, diaphragm or lever arm The lever arm can break off and fall into the sump. The downside of a failed diaphragm (apart from the engine not running!) is that petrol will drain from the pump into the sump. Dip the oil and see if it smells of petrol.Malcolm Link to comment Share on other sites More sharing options...
Red Line Components Posted October 25, 2016 Author Share Posted October 25, 2016 Thanks, I wouldn't be surprised if it is crud in the tank that caused the breakdown but something (else?) is preventing it from starting now. Link to comment Share on other sites More sharing options...
Red Line Components Posted October 25, 2016 Author Share Posted October 25, 2016 Thanks for the reply Malcolm, I will pull the pump off and have a look. (At least I have a spare) Link to comment Share on other sites More sharing options...
Englishmaninwales Posted October 25, 2016 Share Posted October 25, 2016 There are overhaul kits available for the AC pump, have a look on eBay. Pick one that includes a seal for the diaphragm push rod ( not all do). The valves are held in with a tang, it is possible to get them out to replace.Malcolm Link to comment Share on other sites More sharing options...
Red Line Components Posted October 25, 2016 Author Share Posted October 25, 2016 Tang? Link to comment Share on other sites More sharing options...
SM25T Posted October 25, 2016 Share Posted October 25, 2016 A metal tag. Link to comment Share on other sites More sharing options...
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